#!/bin/bash

awk '{
    if($0 ~ /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$/){
        split($0, arr, ".")
        is_valid = 1
        for(i=1; i<=length(arr); i++){
            if(arr[i]<0 || arr[i]>255){
                print "no"
                is_valid = 0
                break
            }
        }
        if(is_valid){
            print "yes"
        }
    } else {
        print "error"
    }
}' nowcoder.txt